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Fixes for VirtualAlloc function: 

* mplayer received a SIGSEGV under Linux after
	Opening video decoder: [dmo] DMO video codecs
	VirtualAlloc(0x00400000, 859648, 0x00003000, 0x00000040)
      because that region was already under use and mmap() with
      MAP_FIXED has problems under Linux (see code).
      VirtualAlloc() fixed in "loader/ext.c".

    * VirtualAlloc() made to conform with win32 documented behavior
      regarding the alignment of the address and size arguments.

    * VirtualAlloc() detection of overlap with previous regions fixed.

Patch by A. Guru ( a.guru at sympatico dot ca )


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@13304 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
rtognimp 2004-09-10 16:39:31 +00:00
parent 052031df6d
commit 9e9aec9bf9
1 changed files with 48 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
loader/ext.c
View File

@ -457,13 +457,32 @@ static virt_alloc* vm=0;
LPVOID WINAPI VirtualAlloc(LPVOID address, DWORD size, DWORD type, DWORD protection)
{
void* answer;
int fd=open("/dev/zero", O_RDWR);
int fd;
long pgsz;
//printf("VirtualAlloc(0x%08X, %u, 0x%08X, 0x%08X)\n", (unsigned)address, size, type, protection);
if ((type&(MEM_RESERVE|MEM_COMMIT)) == 0) return NULL;
fd=open("/dev/zero", O_RDWR);
if(fd<0){
perror( "Cannot open /dev/zero for READ+WRITE. Check permissions! error: " );
return NULL;
}
size=(size+0xffff)&(~0xffff);
//printf("VirtualAlloc(0x%08X, %d)\n", address, size);
if (type&MEM_RESERVE && (unsigned)address&0xffff) {
size += (unsigned)address&0xffff;
(unsigned)address &= ~0xffff;
}
pgsz = sysconf(_SC_PAGESIZE);
if (type&MEM_COMMIT && (unsigned)address%pgsz) {
size += (unsigned)address%pgsz;
address -= (unsigned)address%pgsz;
}
if (type&MEM_RESERVE && size<0x10000) size = 0x10000;
if (size%pgsz) size += pgsz - size%pgsz;
if(address!=0)
{
//check whether we can allow to allocate this
@ -475,7 +494,7 @@ LPVOID WINAPI VirtualAlloc(LPVOID address, DWORD size, DWORD type, DWORD protec
str=str->prev;
continue;
}
if((unsigned)address+size<(unsigned)str->address)
if((unsigned)address+size<=(unsigned)str->address)
{
str=str->prev;
continue;
@ -483,29 +502,40 @@ LPVOID WINAPI VirtualAlloc(LPVOID address, DWORD size, DWORD type, DWORD protec
if(str->state==0)
{
#warning FIXME
if(((unsigned)address+size<(unsigned)str->address+str->mapping_size) && (type & MEM_COMMIT))
if( ((unsigned)address >= (unsigned)str->address)
&& ((unsigned)address+size<=(unsigned)str->address+str->mapping_size)
&& (type & MEM_COMMIT))
{
close(fd);
return address; //returning previously reserved memory
}
return NULL;
//printf(" VirtualAlloc(...) does not commit or not entirely within reserved, and\n");
}
/*printf(" VirtualAlloc(...) (0x%08X, %u) overlaps with (0x%08X, %u, state=%d)\n",
(unsigned)address, size, (unsigned)str->address, str->mapping_size, str->state);*/
close(fd);
return NULL;
}
answer=mmap(address, size, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, fd, 0);
}
else
answer=mmap(address, size, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE, fd, 0);
answer=mmap(address, size, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE, fd, 0);
// answer=FILE_dommap(-1, address, 0, size, 0, 0,
// PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE);
close(fd);
if (answer != (void *)-1 && address && answer != address) {
/* It is dangerous to try mmap() with MAP_FIXED since it does not
always detect conflicts or non-allocation and chaos ensues after
a successful call but an overlapping or non-allocated region. */
munmap(answer, size);
answer = (void *) -1;
errno = EINVAL;
//printf(" VirtualAlloc(...) cannot satisfy requested address but address=NULL would work.\n");
}
if(answer==(void*)-1)
{
printf("Error no %d\n", errno);
printf("VirtualAlloc(0x%p, %ld) failed\n", address, size);
printf(" VirtualAlloc(...) mmap(0x%08X, %u, ...) failed with errno=%d (\"%s\")\n",
(unsigned)address, size, errno, sys_errlist[errno]);
return NULL;
}
else
@ -524,14 +554,17 @@ LPVOID WINAPI VirtualAlloc(LPVOID address, DWORD size, DWORD type, DWORD protec
vm->next=0;
//if(va_size!=0)
// printf("Multiple VirtualAlloc!\n");
//printf("answer=0x%08x\n", answer);
//printf(" VirtualAlloc(...) provides (0x%08X, %u)\n", (unsigned)answer, size);
return answer;
}
}
WIN_BOOL WINAPI VirtualFree(LPVOID address, SIZE_T dwSize, DWORD dwFreeType)//not sure
{
virt_alloc* str=vm;
int answer;
//printf("VirtualFree(0x%08X, %d, 0x%08X)\n", (unsigned)address, dwSize, dwFreeType);
while(str)
{
if(address!=str->address)
@ -539,7 +572,7 @@ WIN_BOOL WINAPI VirtualFree(LPVOID address, SIZE_T dwSize, DWORD dwFreeType)//n
str=str->prev;
continue;
}
//printf("VirtualFree(0x%08X, %d - %d)\n", str->address, dwSize, str->mapping_size);
//printf(" VirtualFree(...) munmap(0x%08X, %d)\n", (unsigned)str->address, str->mapping_size);
answer=munmap(str->address, str->mapping_size);
if(str->next)str->next->prev=str->prev;
if(str->prev)str->prev->next=str->next;